[Usefulness of the electrophysiologic study in the prognostic evaluation of patients with syncope of uncertain origin].

UNLABELLED

Recurrent, sudden temporary loss of consciousness is a common clinical problem: in the absence of electrocardiographic monitoring during a syncopal episode (S), abnormalities demonstrated by an electrophysiological study (ES) may suggest the etiology of S. We have performed a complete ES in 53 Pts (M. 38-F. 15, mean age 63 y.) with recurrent unexplained S (3.8 S/pt) by means of a standardized protocol. Group I: 30 Pts (mean age 65 y, 3.6 S/pt) with structural heart disease. Thirteen of these had abnormal ES findings: inducible ventricular tachycardia in 6, prolonged HV interval in 7 (with bundle branch block), very fast atrial flutter in one. Group II: 23 Pts (mean age 61 y., 3, 9 S/pt), without organic heart disease. The ES was abnormal in 14 Pts showing a prolonged HV interval in 11 (with bundle branch block), an intrahisian block in 1 and an inducible AV nodal tachycardia with heart rate greater than 200/m' in one. Only the Pts with abnormal ES were treated according to their condition with amiodarone or with an implantable pacemaker. Three PTs with C.H.D. and normal ES successfully underwent by-pass surgery. During the follow-up (20 months) therapy based on ES provided symptomatic relief (no S) in 25 of 26 Pts with abnormal electrophysiological study. Syncope persisted in 4 of 26 Pts in whom ES did not define a mechanism of S. No sudden death in any Pt.

CONCLUSIONS

ES was, therefore, of diagnostic value in more than half of the patients with syncope of unknown cause and long-term treatment based on ES was successful in the prevention of S (remission rate of 93% in patients treated with amiodarone or pacemaker).